Power Outages in the wake of Hurricane Michael

October 12th, 2018 |

VIIRS Day Night Band Visible (0.70 µm) Imagery from NOAA-20 on 6 October and 12 October 2018 (Click to enlarge)

The VIIRS (Visible-Infrared Imaging Radiometer Suite) instrument onboard NOAA-20 includes a Day Night Band that can be used to assess, among other things, power outages after a strong storm such as Hurricane Michael. The toggle above shows Day Night Band imagery from 6 October (before Michael) and 12 October (after Michael), and the change in illumination from city lights over the Florida Panhandle northeastward into east-central Georgia is stark.

Of course, clouds can also mask city lights in the Day Night Band. However, 11.45 µm infrared imagery from VIIRS, below, on 12 October, shows scant evidence of clouds over the region where city lights are missing.

VIIRS Infrared (11.45 µm) Imagery from NOAA-20, 12 October 2018, 0844 UTC (Click to enlarge)

(NOAA-20 images here courtesy William Straka, CIMSS)

Category 4 Hurricane Michael makes landfall along the Florida coast

October 10th, 2018 |

Sequence of Infrared Window images from Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) [click to enlarge]

Infrared Window images from Terra/Aqua MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm) [click to enlarge]

A sequence of Infrared Window images from Terra/Aqua MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm) (above) showed Category 4 Hurricane Michael as it was making its approach toward the Florida coast during the nighttime hours preceding sunrise on 10 October 2018. The yellow pixels east of the eye on the 0724 UTC VIIRS image highlighted cloud-top infrared brightness temperatures of -90ºC and colder (with a minimum of -92ºC).

Toggles between VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP (below; courtesy of William Straka, CIMSS) revealed convectively-generated mesospheric airglow waves propagating away from the hurricane.

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Overlapping GOES-16 (GOES-East) Mesoscale Domain Sectors provided 30-second interval  “Clean” Infrared Window (10.3 µm) and “Red” Visible (0.64 µm) images of Michael after sunrise (below).

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

GOES-16 "Red" Visible (0.64 µm) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

Closer views of GOES-16 Visible and Infrared images (below) showed Hurricane Michael making landfall around 1730 UTC as a high-end Category 4 storm near Mexico Beach, Florida — with maximum sustained winds of 135 knots (155 mph) and a minimum central pressure of 919 hPa (27.41 inches). During the 24-hour period prior to landfall, Michael had been moving over water having moderate Ocean Heat Content and warm Sea Surface Temperatures; and as had been the case during much of Michael’s time as a hurricane, in spite of the fact that deep-layer wind shear (09 October | 10 October landfall) was somewhat unfavorable, the storm was still able to maintain a trend of intensification (ADT | SATCON).

GOES-16 "Red" Visible (0.64 µm) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

GOES-16 "Clean" Infrared Window (10.3 µm) images [click to play MP4 animation]

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

As pointed out on Twitter by the SOO at NWS Nashville, GOES-16 Visible imagery (below) revealed the bright white sandy beaches of Saint Andrew Sound (Google Maps) as the eye of Michael passed overhead. Surface observations from Panama City (KECP), Tyndall AFB (KPAM) and Apalachicola (KAAF) are plotted on the images — all 3 sites stopped reporting after landfall, presumably due to power outages (the peak wind gust at Tyndall AFB was 129 mph). A longer animation (from 1300-1959 UTC) of 30-second GOES-16 Visible images is available here (courtesy of Pete Pokrandt, UW-AOS).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with surface observations and with/without a map overlay [click to play animation | MP4]

The signature of the beaches was also evident on GOES-17 Visible imagery (below) —  but since that satellite was scanning at the standard 5-minute interval, they were only seen on 2 consecutive images. Note that GOES-17 imagery shown here  is preliminary and non-operational.

GOES-17 "Red" Visible (0.64 µm) images, with surface observations and with/without a map overlay [click to enlarge]

GOES-17 “Red” Visible (0.64 µm) images, with surface observations and with/without a map overlay [click to enlarge]

One item of local curiosity that was observed on GOES-16 Visible imagery: a darker shadow-like feature within the eye, which slowly migrated from the northern to the western portion during the 1613-1642 UTC period (1625 UTC still image | MP4 animation). Closer inspection of the GOES-16 ABI Near-Infrared and Infrared spectral bands (below) indicated that this was indeed a cloud shadow, from a cirrus filament that became detached from the southeastern edge of the eyewall and then rotated cyclonically within the eye to cast a shadow against the brightly-illuminated quasi-vertical edges of the eyewall.

16-panel images of all GOES-16 ABI spectral bands [click to play animation | MP4]

All 16 spectral bands of the GOES-16 ABI [click to play animation | MP4]

A sequence of Infrared Window images from Aqua MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm) (below) provided a high-resolution view of the cold cloud tops associated with Michael during and shortly after landfall.

Infrared Window images from Aqua MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm) [click to enlarge]

Infrared Window images from Aqua MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm) [click to enlarge]

On a larger scale, GOES-16 mid/upper-level Derived Motion Winds from the CIMSS Tropical Cyclones site (below) revealed the development of a well-defined outflow channel to the north of the storm, especially during the 12 hours prior to landfall — this enhanced poleward outflow (aided by the approach of an upper-level trough from the central US) may have been a contributing factor in Michael’s continued intensification leading up to landfall.

GOES-16 Mid/Upper-level winds, 21 UTC on 09 October to 21 UTC on 10 October [click to enlarge]

GOES-16 Mid-level (6.9 µm) Water Vapor images with Mid/Upper-level winds, from 21 UTC on 09 October to 21 UTC on 10 October [click to enlarge]

Aqua MODIS Near-Infrared “Cirrus” (1.37 µm) and Water Vapor (6.7 µm) images (below) showed that clouds and moisture were being transported by this outflow channel as far northward as the Ohio River Valley shortly after the time of landfall.

Aqua MODIS Near-Infrared

Aqua MODIS Near-Infrared “Cirrus” (1.37 µm) and Water Vapor (6.7 µm) images [click to enlarge]

A GOES-16 Red-Green-Blue (RGB) animation (below; courtesy of Rick Kohrs, SSEC) showed the landfall of Michael.

GOES-16 RGB images [click to play MP4 animation]

GOES-16 RGB images [click to play MP4 animation]

A stereoscopic animation using GOES-16 and GOES-17 Visible imagery is provided below; to view the animation in 3-D, cross your eyes until 3 images appear — then focus on the image in the middle. Note that GOES-17 images shown here are preliminary and non-operational.

“Red” Visible (0.64 µm) images from GOES-16 (left) and GOES-17 (right) [click to play animation]

===== 11 October Update =====

Aqua MODIS True Color RGB images from 06 October and 11 October [click to enlarge]

Aqua MODIS True Color RGB images from 06 October and 11 October [click to enlarge]

A comparison of Aqua MODIS True Color RGB images from 06 October (before Michael) and 11 October (after Michael) showed a dramatic increase in turbidity of the water off the “Emerald Coast” portion of the Florida Panhandle — this turbidity was the result of turbulent mixing of the relatively shallow continental shelf water by the strong winds of the hurricane. The close-up images above are centered off the coast near the landfall location; the large-scale images below show more of the Gulf Coast, from Texas to the Florida Peninsula.

Aqua MODIS True Color RGB images from 06 October and 11 October [click to enlarge]

Aqua MODIS True Color RGB images from 06 October and 11 October [click to enlarge]

Hourly images of the MIMIC Total Precipitable Water product during the 5-day period from 07-11 October (below) showed the transport of tropical moisture from the Caribbean Sea across the Gulf of Mexico and over the southeastern US — heavy rainfall and flooding occurred from Florida and Alabama to the Mid-Atlantic states (WPC summary).

MIMIC Total Precipitable Water images, 07-11 October [click to play animation | MP4]

MIMIC Total Precipitable Water images, 07-11 October [click to play animation | MP4]

The entire life cycle of Michael can be viewed in a compilation of GOES-16 Infrared 1-minute (or 30-second, when available) Mesoscale Sector images from 07-11 October, available here  — with a zoomed-in version of the images from 08-11 October available here or on YouTube (courtesy of Pete Pokandt, UW-AOS).

Tropical Storm Michael

October 7th, 2018 |

GOES-16 "Clean" Infrared Window (10.3 µm) images [click to play MP4 animation]

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images (above) showed deep convection associated with Tropical Depression 14 east of Belize and the Yucatan Peninsula of Mexico early in the day on 07 October 2018. There was a large area of cloud-top infrared brightness temperatures in the -80ºC to -89ºC range (shades of purple), with isolated small pockets of -90ºC or colder (yellow enhancement).

1-minute GOES-16 “Red” Visible (0.64 µm) images from the UW-AOS site (below) showed numerous convective overshooting tops.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

At 1655 UTC the system was upgraded to Tropical Storm Michael — 1-minute GOES-16 Infrared images (below) showed that deep convection persisted in the eastern semicircle of Michael during the remainder of the day.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

A hint of the elongated low-level circulation could be seen just west of the deep convection on late-day GOES-16 Visible images (below).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

===== 08 October Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm), Infrared Window (11.45 µm) and ATMS Microwave (88 GHz) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm), Infrared Window (11.45 µm) and ATMS Microwave (88 GHz) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm), Infrared Window (11.45 µm) and ATMS Microwave (88 GHz) images at 0721 UTC (above; courtesy of William Straka, CIMSS) indicated that a well-defined convective band was wrapping around the eastern, northern and northwestern portions of the storm center (with some bright lightning streaks showing up on the DNB image in the southeastern segment of this convective band).

In a comparison of DMSP-18 SSMIS Microwave (86 GHz) and GOES-16 Infrared Window (10.3 µm) images at or shortly after 1115 UTC (below), the Microwave imagery showed a very large eye beneath the convective clusters.

DMSP-18 SSMIS Microwave (86 GHz) and GOES-16 Infrared Window (10.3 µm) images [click to enlarge]

DMSP-18 SSMIS Microwave (86 GHz) and GOES-16 Infrared Window (10.3 µm) images [click to enlarge]

Michael was upgraded to a Category 1 hurricane at 15 UTC; 1-minute GOES-16 “Red” Visible (0.64 µm) images (below) revealed abundant deep convection around the core of the storm during the 3 hours leading up to that time.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

Michael had been moving over very warm water since forming on 06 October; analyses of Ocean Heat Content and Sea Surface Temperature (below) showed that while the hurricane was forecast to briefly pass over a region of lower OHC in the far southeastern Gulf of Mexico, the remainder of its journey across the Gulf would be over water possessing modest amounts of OHC and warm SST values of 29-30ºC.

Ocean Heat Content and Sea Surface Temperature analyses, with past and forecast tracks of Michael [click to enlarge]

Ocean Heat Content and Sea Surface Temperature analyses, with past and forecast tracks of Michael [click to enlarge]

Similarly, a relatively cloud-free Terra MODIS Sea Surface Temperature product from 0343 UTC on 06 October (below) showed SST values of 84-85ºF (darker red colors) along much of the forecast path of Hurricane Michael (issued at 2100 UTC on 08 October).

Terra MODIS Sea Surface Temperature product (0343 UTC on 06 October) with Hurricane Michael forecast positions issued at 2100 UTC on 08 October [click to enlarge]

Terra MODIS Sea Surface Temperature product (0343 UTC on 06 October) with forecast positions of Hurricane Michael issued at 2100 UTC on 08 October [click to enlarge]

Hurricane Walaka

October 1st, 2018 |

GOES-15 Infrared Window (10.7 µm) images [click to play animation | MP4]

GOES-15 Infrared Window (10.7 µm) images [click to play animation | MP4]

GOES-15 (GOES-West) Infrared Window (10.7 µm) images (above) showed the formation of a well-defined eye of Hurricane Walaka during a period of rapid intensification (ADT | SATCON) from 0000-2330 UTC on 01 October 2018; Walaka was classified a Category 5 hurricane as of the 02 October 00 UTC advisory. Walaka was moving over very warm water with Sea Surface Temperatures of 30ºC.

A 1536 UTC DMSP-16 SSMIS Microwave (85 GHz) image from the CIMSS Tropical Cyclones site (below) revealed a small eye (reported to be 20 nautical miles in diameter at 21 UTC).

DMSP-16 SSMIS (85 GHz) Microwave image [click to enlarge]

DMSP-16 SSMIS (85 GHz) Microwave image [click to enlarge]

A side-by-side comparison of JMA Himawari-8 and GOES-15 Infrared Window images (below) showed Walaka from 2 different satellite perspectives — the superior spatial resolution of Himawari-8 (2 km, vs 4 km for GOES-15) was offset by the much larger viewing angle. Cloud-top infrared brightness temperatures were -80ºC and colder (shades of violet) from both satellites early in the animation, but warmed somewhat into the -70 to -75ºC range by 00 UTC on 02 October.

Infrared Window images from Himawari-8 (10.3 µm, left) and GOES-15 (10.7 µm, right) [click to play animation | MP4]

Infrared Window images from Himawari-8 (10.3 µm, left) and GOES-15 (10.7 µm, right) [click to play animation | MP4]

===== 02 October Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Walaka remained classified as a Category 5 hurricane until the 15 UTC advisory on 02 October, when it was assigned Category 4 status after some weakening as a result of an overnight eyewall replacement cycle. A toggle between NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (above; courtesy of William Straka, CIMSS) showed the storm at 1240 UTC or 2:40 am local time.

GOES-15 Infrared Window (10.7 µm) images (below) showed the northward motion of Waleka. Given that the storm was forecast to pass very close to Johnston Atoll, the US Coast Guard was dispatched to evacuate personnel on Johnston Island.

GOES-15 Infrared Window (10.7 µm) images; the white circle shows the location of Johnston Atoll [click to play animation | MP4]

GOES-15 Infrared Window (10.7 µm) images; the white circle shows the location of Johnston Atoll [click to play animation | MP4]

The MIMIC-TC product (below) showed the eyewall replacement cycle during the 0000-1445 UTC period.

MIMIC-TC morphed microwave product [click to play animation]

MIMIC-TC morphed microwave product [click to play animation]

Around 1830 UTC, a toggle between GOES-15 Infrared (10.7 µm) and GPM GMI Microwave (85 GHz) images (below) showed a small eye, with evidence of a larger outer eyewall suggesting that another eyewall replacement cycle was taking place.

GOES-15 Infrared Window (10.7 µm) and GPM GMI Microwave (85 GHz) images [click to enlarge]

GOES-15 Infrared Window (10.7 µm) and GPM GMI Microwave (85 GHz) images [click to enlarge]